The AR gene located on the X chromosome provides instructions for making the androgen receptor protein. Androgens are hormones (such as testosterone) that are important for normal male sexual development before birth and during puberty. Mutations that completely eliminate the function of the androgen receptor cause complete androgen insensitivity syndrome (also known as androgen resistance syndrome). Genetic changes that significantly reduce but do not eliminate the receptor's activity cause partial androgen insensitivity syndrome. Mild androgen insensitivity syndrome results from changes that only slightly reduce the activity of the receptor.GHR